Broiler Litter and Contaminated Feed Implicated in Recent Cases of Botulism in Cattle
SAC Veterinary Services is urging farmers to be aware of the risks of botulism in cattle that are in contact with broiler litter or animal feed contaminated with wild bird or rodent carcases. Although, until recently, relatively rare in Scotland, four cases of botulism in cattle have been investigated by SAC in the last month. In two of these outbreaks contact with broiler litter was the suspected source of infection. In the other two cases, the source appears to be home mixed feed or silage which has become contaminated with carcase material.
This increase in Scotland follows on from reports of an increase, in recent years, in the number of cases of botulism in cattle and sheep, mostly associated with broiler litter, in England and Wales and in Northern Ireland. In some of these cases mortality rates have been high. For example in one outbreak in England, 88 animals in a flock of 230 ewes either died or had to be destroyed.
Ruminant farmers, poultry producers and veterinary surgeons are urged to take precautions to minimise the risk of botulism through contact with broiler litter or carcase material.
SAC has issued the following guidelines.
Guidelines for ruminant farmers:
ľ If at all possible do not import poultry litter onto ruminant farms
ľ Move stock away from nearby fields, including those on neighbouring premises, if litter is stored or spread on fields
ľ If using litter for fertiliser do not spread on pasture used for grazing or from which forage is conserved and keep stock as far from it as possible
ľ When using as fertiliser on arable fields plough in the litter as soon as possible
ƒæ If storing litter or feed components for a period on the farm, these must be secure ¡V
o the storage facility should prevent access by scavenging birds and animals
o site litter store as far as possible from livestock on home and neighbouring farms
o comply with relevant environmental regulations (PEPFAA Good Practice Code)
o store litter in a secure enclosure constructed with wooden sleepers, concrete or earth walls
o secure litter store once filled to deter access by scavengers e.g. cover with cattle manure and slurry, or use properly weighted and secured strong tarpaulin
ľ Remove litter to arable land and plough immediately avoiding a period of storage on pasture when scavenging animals and birds could gain access.
ľ Ensure that machinery used for litter is not used for storing, mixing or moving feedstuffs
ľ Do not use litter as bedding for ruminants
ľ Adopt good personal hygiene when moving or spreading litter
ľ Contact your veterinary surgeon if you suspect cases of botulism in your livestock
Additional Recommendations for Poultry Producers:
ľ It is illegal to dispose of litter with carcase material as fertiliser (Animal By-Products Regulations)
ľ Ideally, remove litter from buildings and transport immediately to an incineration site
ľ If unable to transport off the farm immediately, securely store litter after removal from housing, as detailed previously for ruminant farmers.
Guidelines for Veterinary Surgeons
Suspect cases of botulism in livestock should be reported to your nearest SAC Veterinary Services Centre for further investigation. SAC acts on behalf of Food Standards Agency Scotland who will carry out a risk assessment in relation to potential threats to the human food chain of such cases.
For veterinary surgeons whose clients are faced with the risk of further outbreaks of botulism in ruminants, such as those with broiler units who dispose of their own litter as fertiliser, or for premises adjacent to broiler units, a bivalent Clostridium botulinum types C and D vaccine is available for use in cattle and sheep. The vaccine is manufactured by Fort Dodge and can be obtained by applying to the Veterinary Medicines Directorate for a ¡¥Special Treatment Certificate (STC). Application forms are available on line at www.vmd.gov.uk under general information/applications page. Further information is available in Veterinary Medicines Guidance Note (VMGN) 7.
